The present disclosure relates to electronic device sockets for electronic devices and more particularly to pin sockets.
Pin sockets are used to provide the ability to 1) attach an electronic device to a printed circuit board (PCB) without exposing the device leads to high solder temperatures, and 2) remove the device, as needed, without having to de-solder the device from the PCB. Traditionally, pin sockets are sold as discreet units or are connected to each other with an insulating material such as molded plastic or machined laminate.
Traditional pin sockets are designed and built as a two-piece electrical contact assembly consisting of a contact with multiple tapered fingers 2 press-fitted into the axial hole of a turned pin metal terminal 3, as shown in FIG. 1A. When a device lead is inserted into the pin socket which is soldered to the PCB 10, see e.g. FIG. 1B, it travels down the tapered fingers to the distal end of the contact through a lumen 4. Along the way, the device lead makes frictional contact with the proximal end 2p of the tapered fingers 2. This friction, or “wiping action,” impacts the insertion, retention, and extraction forces, respectively i.e., the respective forces required to insert, keep in place, and withdraw a device lead to and from a socket. During insertion, the frictional forces between device lead and contact 1 is highest at the proximal end 2p, i.e., entry point, of the contact. The high mechanical force required to insert the device lead into the contact 1 entrance can damage the device lead or crack the device substrate.
Manufacturing a traditional pin socket conventionally requires eight (8) distinct manufacturing steps:
1) stamping metal to create a multi-finger contact,
2) forming the metal in order to taper the fingers,
3) heat treating the stamped and formed contact,
4) plating the contact,
5) machining a turned pin metal terminal,
6) plating the terminal,
7) inserting the plated contact into the plated terminal, and
8) probing each contact with a gauge pin in order to deflect the fingers enough to achieve a specified insertion, retention, and/or extraction force.
Each of these steps requires tight process and quality control. The probing step 8) is especially labor-intensive and adds significant cost to the manufacturing process of the socket. Further, correlating the customer's desired insertion, retention, and withdrawal force to a probing protocol involves a lot of trial-and-error, and yields both inconsistent results and added costs.
Therefore, there is a need for an improved design of a pin socket which reduces cost, reduces the complexity of manufacture, and increases the consistency of the results.
In a first embodiment, an electronic device socket is provided. The electronic device socket includes a barrel. The barrel includes a lumen, a proximal barrel, a tapering region, a plurality of fingers, and a dimple contact area. The barrel includes a lumen extending therethrough. The proximal barrel portion has a first diameter. The tapering region extends distally from the proximal barrel portion and, the tapering region extending both distally and radially inward towards a central axis of the barrel to define a second diameter which is smaller than the first diameter. The plurality of fingers extend distally from the tapering region and the plurality of fingers are all parallel to one another and the central axis. The dimple contact area extends from each of the plurality of fingers extending radially inward and distally.
In some embodiments, the plurality of fingers can be three fingers. In some cases, each of the dimples extend radially outward at a location distal to the radially inward section. The barrel can be configured to make full contact with an electronic pin only at the dimple contact area.
In still further embodiments the contact can be disposed in a printed circuit board by surface mounting or in a through-hole. The contact can include a solder tail extending distally therefrom to attach the contact to the printed circuit board. The contact can be soldered to the printed circuit board. The contact can include a tapered plug disposed in a distal end thereof. The contact can include a locking feature which locks the tapered plug into an undercut of the distal end of the contact. The socket can be one piece. The socket can be press fitted into an outer shell.
In another exemplary embodiment a one piece parallel multi-finger contact configured for mounting electronic devices to a printed circuit board is disclosed. The contact includes a barrel including a plurality of parallel beams and a point of contact. The barrel includes a first diameter. The plurality of parallel beams extend distally from the barrel, the plurality of beams are disposed about a second diameter which is smaller than the first diameter. The point of contact is distal to the plurality of parallel beams defined by a respective dimple on each of the plurality of parallel beams. The point of contact is radially inward of both the barrel and the plurality of parallel beams.
In some embodiments, the plurality of parallel beams can be parallel to a central axis of the contact. The plurality of parallel beams can be parallel to one another along a majority of the length of the contact. Each of the respective dimples can extend radially inward and distally from a respective parallel beams and then radially outward and distally. The plurality of parallel beams can be three parallel beams.
A method of manufacturing a one piece parallel multi-finger contact is additionally provided. The method includes only the steps of stamping a piece of metal to create a multi-finger contact; forming a dimple on a distal end each of the fingers of the multi-finger contact; heat treating the multi-finger contact; and plating the contact.
In some embodiments, the multi-finger contact can include a barrel, a plurality of fingers extending distally therefrom. Each of the fingers can be parallel to one another, and a respective dimple can extend distally from each of the plurality of fingers. In further embodiments the plurality of fingers can be parallel to one another along a majority of the length of the contact. Each of the respective dimples can extend radially inward and distally from a respective finger and then radially outward and distally. The steps of the disclosed method may be performed in any order.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.